Self-adjusting wrench



April 19, 1949.v F. J. CARNELLI 2,467,658

SELF ADJUSTING WRENCH Filed Feb. 7, 1946 I 2 Sheets-Sheet 1 INVENTOR: PEA/N05 J (GE/V54 L ATTORNEY.

April 1949. F. J. CARNELL! 2,467,658

' SELF ADJUSTING WRENCH I Filed Feb. 7, 1946 2 Sheets-Sheet 2 A TTORNEY.

Patented Apr. 19, 1949 UNITED STATES PATENT OFFICE 2 Claims.

My present invention relates to a self-adjusting wrench having a movable jaw which will receive nuts or bolts heads of different sizes and configurations and grip them when force is applied to the wrench.

In the wrench of my invention I provide a hollow handle having at one end a curved or cam-shaped jaw face and also having a passageway adjacent this face in which is pivoted a spring pressed rocking jaw. This rocking jaw has a face which is preferably flat and which, as the jaw is rocked, swings about the cam surface of the fixed jaw, the pivoting of the rocking jaw being such that the distance from the cam face of the fixed jaw to the gripping face of the rocking jaw progressively increases. A spring mounted in the handle and bearing against the rocking jaw serves to urge it to closing position, that is, towards a position in which the gripping face approaches the cam face of the fixed jaw.

The handle of the wrench is hollow, preferably made from a pair of symmetrically opposite channel shaped elements. Near the end carrying the fixed jaw a passageway is formed to receive the tail portion of the rocking jaw. The fixed jaw is secured between the projecting walls of the handle by welding or other suitable means.

A spring for pressing the rocking jaw toward closing position is mounted in the handle. For this purpose it has a reversely bent part in the handle and one end projecting into the passageway and engaging the rocking jaw while the other end is bent to form a clip to engage the edge of one of the walls near the opening.

With this construction a pin is secured in the handle without rivets or fastening, and the pin may be slipped axially outwardly for removal or replacement of the rocking jaw.

The various features of the invention are illustrated, by way of example, in the accompanying drawings in which Fig. 1 is a sid view of a wrench embodying a preferred form of the invention;

Fig. 2 is a longitudinal section taken on line 2-2 of Fig. 1; r

Fig. 3 is a longitudinal section taken on a plane at right angles to the plane of Fig. 2 and showing the position of the rocking jaw when engaging a small size hexagonal nut;

Fig. 4 is a side view of the fixed jaw detached from the wrench;

Fig. 5 is a view of a handle forming element;

Fig. 6 is a plan view of a reinforcement for the handle;

Fig. 7 is a cross-section taken on line 1-1 of Fig. 3;

Fig. 8 is a side view of the wrench in position to engage a square nut of larger dimension than the hexagonal nut of Fig. 3;

Fig. 9 is a view of the wrench showing the position of the rocking jaw and engaging a hexagonal nut of the maximum size;

Fig. 10 is a section of the wrench taken on line ill-l0 of Fig. 8.

In the embodiment of the invention shown in the accompanying drawings the wrench comprises a handle element l l of hollow construction. This handle is preferably formed of a pair of hollow stampings I2 and 13 of reverse or symmetrical form joined at their edges by welding as at M. The resulting structure is one having a pair of substantially fiat parallel top and bottom walls l5 and I6 and a pair of side Walls l'l and I8. Suitable finger notches l9 and 20 may be formed by curves in the side walls I? and I8; four such finger notches being illustrated on each wall, by way of example.

The side walls ll and i8 terminate at 2i and 22 and the top and bottom walls l5 and I6 extend beyond the edges 2| and 22 in a flat parallel relationship to a fixed jaw 23.

Reinforcing plates 24 and 25 may be secured or welded to the part of the handle extending to the jaw 23 and form the faces of a horizontal passageway 26.

In the passageway 26 is mounted a rocking jaw 21. This jaw has at one end a gripping face 28, preferably a flat or substantially fiat face, and extending at an angle of degrees is a second or stop face 29. The jaw then extends in a curved direction to form a tail piece 30 which extends through the passageway 26.

A pivot pin 3| is fixed in openings in the walls l5 and i6 and reinforcing plates 24 and 25 and extends through a suitable opening in the jaw 27. Preferably the tail of the jaw extends somewhat through the passage to provide an end 32 which may be pressed by the thumb, as indicated in Fig. 8, to rock the jaw to a desired position.

The rocking jaw is swung toward closing position by means of a spring 33 havin a reversely bent or looped portion 34 in the hollow part of the handle II and from which one end extends to the edge 2! of the handle and is bent to form a clip 35 to engage the side wall l'l, while the other end extends upwardly and is engaged by a camlike surface 36 of the rocking jaw 21. The action of the spring is such as to swing the rocking jaw 27 counterclockwise in the position shown in Figs. 1 and 3.

The fixed jaw 23 has a curved or cam shaped surface 3'! facing or opposed to the faces 28 and 29 of the rockin jaw. This cam surface 3'! is so curved that as the rocking jaw swings toward open position the face 28 will be at all times parallel to a plane tangent to the cam surface 31.

For example as shown in Fig. 3 a hexagonal nut 38 placed between the jaws will have one face fiat against the gripping face 28 of the rocking jaw and tangent to the surface 3'! at a point indicated at 39 in Fig. 3.

When pressure is applied to the handle in the direction indicated by the arrow in Fig. 3, the face 28 will hang or be supported on the flat face of the hexagonal nut with the principal pressure coming on that part of the face nearest its junction with the face 29. On the opposite side of the nut the handle will apply an equal pressure at the point 39.

It will be noted that these points of application of pressure are on opposite sides of the opening in the nut and are at some distance from the edges. Consequently a torque will be effectively applied without changing the size or shape of the bore of the nut and at a sumcient distance from the edges to avoid slipping around the corner of the nut.

When the handle is swung in the reverse direction the jaws will open and permit the wrench to swing around the nut until a new face or set of faces is engaged.

It will be noted that if a line were dropped from the point 39 normal to the face 28 it would be distant from the angle or junction of the faces 28 and 29 a length equal to about one-half the distance from the point 39' to the face 28.

It may be noted thatthe handle is bent or offset somewhat between the jaw 31 and the main part of the handle near. approximately the center line of the handle, but it will be understood that any desired configuration can be given. to this part of the handle.

When the wrench is applied, to a nut, 49, of larger dimensions the rocking jaw 21 will swing to a more open position. But, as indicated in Fig. 9, the point of tangency will in this case be at 4! or in. substantially the same relative position to the nut 40 as in the case of the smaller nut 38. The cam or curved surface 31 is so shaped that this will hold true, of. all intermediate sizes of nuts.

A square nut such as the nut 42 has sides which are equal tothe distance between the opening of the-jaws and consequently in order to bring the point of application of the pressure of the cam surface 3'! betweenthe center line of the face and the edge of the nut a. groove 43 is cut into the angle between the facesZB-and 29,, which permits the nut 62 to slide or move somewhat further into the opening of the jaws. This enables a square nut to be engaged with the application of pressure from the opposite jaw faces in approximately thesame manner asin the case of the hexagonal nuts.

It may be noted in Figs. 2 and 4 that the fixed jaw 3'! may be formed of a separate piece, preferably of hardened steel, having a wide face 44 and flange 45 extending between the plates 24 and 25 and welded or otherwise secured thereto.

Itwill also be noted'that the tail portion of the rocking jaw 21 maybe made thinner than the jaw portion in order to pass into the passageway. 24.

Through the above invention I have provided a wrench which is lightin Weight and yet of relatively great strength, and which engages without mechanical adjustment hexagonal and square nuts or nuts of other. configuration in a variety of sizes.

For example my wrench may engage nuts ranging from 4 inch to inch without any adjustments of the wrench andwithout danger of slippin or turning corners or edges of the nuts. Also the wrench is one that may be readily taken apart for the replacement of the spring 33, if the latter should become weakened or broken.

For replacement of the spring 33, all that is necessary is to push out the pin 3| and withdraw the rocking jaw 21. The spring 33 may then be pulled out of the handle and replaced. It is held in place by its reaction on the rocking jaw and on the edge 2|. The pin 31 will stay in place without fastening owing to the reversed or opposed pressures of the rocking jaw and the handle, It may, of course, be peened or otherwise fastened in the openings in the handle.

What I claim is:

1. A self-adjusting wrench which comprises a hollow handle having a pair of substantially flat spaced walls, a jaw fixed at one end of said handle, a portion of said handle bein removed between said flat walls to form a transverse passage- Way near said' jaw; a pair of reinforcing plates within the hollow handle at said transverse passageway, one plate being joined to each of said opposite Walls; a rocking jaw having a face opposed to the fixed jaw of said handle and having a tail portion extending into said transverse passageway; a pivot pin extending through said tail and through said reinforced walls of said handle; and a sprin having a substantially U-shaped loop in said hollow handle, one end being bent to form a clip about the edge of said handle adjacent said transverse passageway, the other end of said spring bearing against the tail portion of said. rocking jaw.

2. A self adjusting wrench which comprises a handle having at one end a fixed jaw and a pair of spaced walls adjacent said jaw to form a transverse slot and having a recess extending from said slot into said handle;. a rocking jaw havin a. gripping face opposed to said fixed jaw of said handle and having a portion extendin into said slot and being pivoted therein and a U-shaped leaf spring confined in said recess with one arm bearing against one side face of said recess andextending over the edge of said recess andreversely thereof onv the outer face of said handle and the other arm of said spring bearing against the opposite face of said recess and extending transversely ofsaidrecess to the extendin portion of said rocking jaw to press said rookingjaw to closing position.

FRANCIS J. CARNELLI.

REFERENCES CITED Thefollowing references are of record in the file of this; patent:

UNITED STATES PATENTS Number Name Date 463,137 Carpenter W Nov. 17,1891 504,232 McKercher Aug..29, 1893 1,281,020 Johnson- Oct. 8, 1918 1,406,467 Matthey- Feb. 14, 1922 1;685,432: Mead Sept. 25, 1928 1,885,616 Mead Nov. 1, 1932 1,900,358 Mead Mar. I, 1933 1,954,141 Miquelon Apr 10, 1934 2,057,899 Lucas Oct. 20, 1936 2,194,049 Mead Mar. 19, 1940 2,211,507 Lilleberg Aug;.13, 1940 FOREIGN PATENTS Number Country Date 236,128 Great Britain July 2,1925 370,963 Great Britain Apr. 11, 1932 389,317 Great Britain Mar. 16, 1933 

